Gas-pressure welding method and device for 60 kg/m hypereutectoid steel rail

A welding method and welding device technology, applied in gas flame welding equipment, welding equipment, metal processing equipment, etc., can solve the problems of difficulty in passing 15 continuous joints through falling hammers, unstable quality of mobile flash welding, and influence on welding quality, etc. Achieve the effect of improving welding quality, less internal defects and stable welding quality

Active Publication Date: 2021-11-09
PANZHIHUA IRON & STEEL RES INST OF PANGANG GROUP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The present invention discloses a 60kg / m hypereutectoid rail pressure welding method, which solves the problem of unstable welding quality of 60kg / m hypereutectoid rail using mobile flash welding, and the internal components of the rail The influence of segregation on welding quality, it is difficult for 15 consecutive joints to pass through the drop hammer

Method used

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  • Gas-pressure welding method and device for 60 kg/m hypereutectoid steel rail
  • Gas-pressure welding method and device for 60 kg/m hypereutectoid steel rail
  • Gas-pressure welding method and device for 60 kg/m hypereutectoid steel rail

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0049] In this embodiment, in order to ensure the quality of gas pressure welding, a special end milling machine is used to mill the rail before welding, and the rust and oxides near the welding joint are polished to 30mm until the metallic luster is exposed. After the treatment, the slope deviation of the end surface of the rail is 0.1mm, and the gap after the seam is 0.2mm. After the end milling is completed, the burrs at the edge of the end of the rail are processed with a file, and the welded end surface is welded immediately after treatment. To avoid secondary pollution such as oil stains after treatment, the rails are hoisted and clamped, and the end sections of the rails are cleaned with carbon tetrachloride before welding. After the end surface treatment is qualified, before ignition welding, the status and performance of the pipeline and equipment should be re-checked. When the operator walks, be careful not to step on various tape pipelines to prevent the heater from ...

Embodiment 2

[0055] In this embodiment, the same steps of welding front end milling and grinding as in embodiment 1 are performed.

[0056] "Detonation ignition" is adopted, and the ignition position is 40mm away from the weld to avoid contamination of the weld. After supplying gas for 4s, ignite the heater of the pressure welding device with an igniter.

[0057] Use an oxy-acetylene flame to heat the part of the rail to be welded, and perform the steps of heating, upsetting welding, pushing and holding pressure in sequence according to the following parameters. The following welding parameters were used for each step:

[0058]

[0059] After the two pressure holdings are completed, after the pressure welding joint is cooled to below 450°C, and the welded joint is completely transformed into pearlite + a small amount of secondary cementite, the rail is reheated for normalizing to avoid coarse grains of the joint after normalizing . After the rail is normalized, it is ground. The grin...

Embodiment 3

[0061] In this embodiment, the same steps of welding front end milling and grinding as in embodiment 1 are performed.

[0062] "Detonation ignition" is adopted, and the ignition position is 40mm away from the weld to avoid contamination of the weld. After supplying gas for 3s, ignite the heater of the pressure welding device with an igniter.

[0063] Use an oxy-acetylene flame to heat the part of the rail to be welded, and perform the steps of heating, upsetting welding, pushing and holding pressure in sequence according to the following parameters. The following welding parameters were used for each step:

[0064]

[0065] The two pressure holdings are completed, and the rail is reheated for normalizing after the air pressure welding joint is cooled below 450°C. After the rail is normalized, it is ground. The grinding surface is the rail head tread and the side of the rail. The grinding profile should keep the original rail head profile as much as possible. The weld bead...

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Abstract

The invention discloses a gas-pressure welding method for a 60 kg/m hypereutectoid steel rail. The method comprises the following steps that firstly, a to-be-welded part of the steel rail is heated through oxy-acetylene flames, wherein a heater of a gas-pressure welding device swings at the amplitude of 3-5 mm, the heating time is 300-350 s, the oxygen flow is 75-90 L/min, and the acetylene flow is 85-95 L/min; when the surface temperature of the to-be-welded part of the steel rail is 1250-1350 DEG C, fuel gas is turned off to stop heating; secondly, upsetting welding is carried out, and primary pressure maintaining is carried out after upsetting welding is completed; thirdly, shearing and secondary pressure maintaining are carried out; and fourthly, heat treatment is carried out on the welding joint of the steel rail. According to the method, the quality of the welding joint of the 60 kg/m hypereutectoid steel rail is effectively improved. The invention also discloses a device for carrying out the method.

Description

technical field [0001] The invention belongs to the field of welding technology, and in particular relates to a 60kg / m hypereutectoid rail gas pressure welding method and a device for executing the method. Background technique [0002] The rise and development of seamless lines represents a major breakthrough and milestone in railway construction and railway construction. The carbon content of the hypereutectoid rail is usually in the range of 0.90-1.10% by weight, the tensile strength is ≥1300MPa, and the tread hardness is ≥390HB. It is suitable for manufacturing high-strength and super-large rails, such as typical 60kg / m hypereutectoid rails. At present, there are three main rail welding methods for seamless lines: flash welding (also known as contact welding, including base flash welding and mobile flash welding), thermite welding and gas pressure welding. Flash welding at the base is mostly used for in-plant welding; thermite welding is used for on-site lock-up welding ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B23K5/00B23K5/22
CPCB23K5/00B23K5/22
Inventor 王若愚李大东陆鑫白威
Owner PANZHIHUA IRON & STEEL RES INST OF PANGANG GROUP
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